I provide a self-hosted version of Remarkbox with a yearly license fee (priced for business to business).

And is the source code available publicly?

The complete source code was not made publicly available.

That said, I'm a strong advocate of open source. Many of the libraries used to create Remarbox are open source, as well as the operating systems used to run the service. I have personally open sourced some of the custom components of Remarkbox with liberal licenses (sometimes even public domain).

At this time I'm trying to make a company out of Remarkbox so that I can eventually run it full time. To accomplish this goal I have decided against providing the complete source code in the open.